Objective: We evaluated the association of maternal pre-pregnancy body mass index (BMI), gestational weight gain (GWG), and maternal smoking with aerobic fitness in young men aged 19-20 years.
Design: A 19-year prospective cohort study.
Setting: Data from the Northern Finland Birth Cohort 1986 (NFBC 1986) and the Sodankylä Jaeger Brigade, Finland, in 2005-6.
Population: Mothers and the 508 offspring in the NFBC 1986 who entered military service at the Sodankylä Jaeger Brigade in 2005.
Methods: Associations of weight, 12-minute running test (Cooper test), and muscle fitness index (MFI) of offspring on entry to military service were evaluated with antenatal factors, including maternal smoking, pre-pregnancy BMI, and GWG.
Main outcome measures: Aerobic and muscle fitness of the offspring were evaluated by the Cooper test and MFI.
Results: Maternal smoking during pregnancy was associated with lower aerobic fitness of male adolescents, measured by the Cooper test (2356 m; 95% confidence interval, 95% CI 2265-2446 m), compared with the offspring of mothers who did not smoke during pregnancy (2537 m, 95% CI 2499-2574 m). This association was independent of the BMIs of both the mother and the offspring, GWG, and the smoking and physical activity of offspring (regression coefficient -140.6 m, 95% CI -273.1 to -8.0 m). High maternal pre-pregnancy BMI and excessive GWG were also associated with lower aerobic fitness of the offspring; however, this association was mediated via the weight of the offspring.
Conclusions: Maternal smoking during pregnancy may have a negative impact on the aerobic fitness of the offspring.
Tweetable abstract: Study shows that young men have lower aerobic fitness if their mothers smoked during pregnancy.
Keywords: Aerobic fitness; gestational weight gain; maternal smoking; offspring; pre-pregnancy BMI.
© 2015 Royal College of Obstetricians and Gynaecologists.